Peripheral Neuropathy (PN)

Definition

Peripheral neuropathy (PN) is a condition/symptom where the nerves that carry messages from the brain and spinal cord to other parts of the body are damaged or diseases. Peripheral nerves are ones found in the muscles, skin and internal organs.

Potential Efficacy / Quality of Evidence (Low, Average, High) of Medical Marijuana for Peripheral Neuropathy (PN) and Neuropathic (Nerve) Pain

Average. Some studies suggest that cannabinoids show particular promise for neuropathic pain when compared to other kinds of pain.

Cannabinoids, Terpenes/Terpenoids, Strains and Ratios that May Help

THC, CBD, CBDV and CBG and other minor cannabinoids could be useful in treating nerve pain.

Alpha- and beta- pinene, beta-caryophyllene, limonene, linalool and myrcene could also be useful for nerve pain and as an analgesic.

CBD:THC 20:1; CBD:THC 18:1; CBD:THC 5:2; CBD:THC 1:1.

Medical Cannabis Pros

Neuropathic pain may have something to do with the vanilloid receptor (TRPV1, the capsaicin receptor) and the ability for the body to keep a consistent internal temperature. CBD desensitizes the TRPV1 receptor, and so may work as a painkiller.

Many medications used for PN and neuropathy have many bad side-effects.

CBD may help induce bone growth and neurogenesis.

Cannabinoids and terpenoids may work in conjunction to help beat nerve pain, which is hard to treat and target.

Topicals and creams can be used to target pain.

Medical Cannabis Cons

Depends on the cause of the nerve pain – some kinds of nerve pain may not respond well to cannabinoids, or the correct ratio is needed for true effectiveness.

Most studies so far have small sample sizes.

More About the Condition

We have written about chronic and muscle pain, as well as headaches and other kinds of pain, but what about nerve pain? Neuropathic pain has quite different treatment methods and patterns, and different classes of medications are used.

Opioids and opiate-based medications are rarely completely effective for neuropathic pain, where antiepileptic/anticonvulsant medications such as pregabalin and gabapentin are used. Tricyclic antidepressants are also used for neuropathic pain. SNRIs may also be useful. As neuropathic pain can often be felt at specific sites on the skin, capsaicin cream may help. High vitamin diets may also help. Steroids may also be prescribed.

Peripheral and neuropathic pain has several causes. Other conditions such as diabetes, multiple sclerosis, Parkinson’s disease, sickle cell anaemia, epilepsy and trigeminal neuralgia are associated with PN and neuropathic pain.

Vitamin deficiencies may also cause PN. Other causes include a traumatic injury, use of some antibiotics such as ciprofloxacin, exposure to certain toxins in the environment and metabolic problems. Neuropathy can affect just one nerve or many nerves.

Quotes from Experts

“Whether drugs capable of exploiting the differences between the various cannabinoid receptors can yield greater analgesia with fewer adverse effects remains to be seen. This capability would be of substantial benefit in the treatment of neuropathic pain, particularly that of central origin, because existing treatments are far from perfect. In the meantime, the current trial adds to the trickle of evidence that cannabis may help some of the patients who are struggling at present.”

‘More evidence cannabis can help in neuropathic pain‘ McQuay, Henry J., CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne vol. 182,14 (2010): 1494-5. doi:10.1503/cmaj.100799

“Use of marijuana for chronic pain, neuropathic pain, and spasticity due to multiple sclerosis is supported by high-quality evidence. Six trials that included 325 patients examined chronic pain, 6 trials that included 396 patients investigated neuropathic pain, and 12 trials that included 1600 patients focused on multiple sclerosis. Several of these trials had positive results, suggesting that marijuana or cannabinoids may be efficacious for these indications.”

Hill KP. ‘Medical Marijuana for Treatment of Chronic Pain and Other Medical and Psychiatric Problems: A Clinical Review.‘ JAMA. 2015;313(24):2474–2483. doi:10.1001/jama.2015.6199